Wire loop, semiconductor device having same, wire bonding method and wire bonding apparatus

ABSTRACT

A wire loop comprises a wire connecting a first bonding point and a second bonding point therethrough, wherein the wire has a crushed part formed therein by crushing the part of the wire and a top of a ball bonded to the first bonding point with a capillary. The wire loop is formed by a wire bonding method which includes: bonding the wire to the first bonding point; moving the capillary horizontally and vertically while carrying out loop control; bonding the wire to the vicinity of the top of the ball bonded to the first bonding point; and thereafter, moving the capillary horizontally and vertically to the second bonding point while delivering the wire and carrying out loop control, and then bonding the wire to the second bonding point.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a wire bonding method for connecting afirst bonding point and a second bonding point through a wire, a wirebonding apparatus for carrying out the method, a wire loop having acertain shape and a semiconductor device having such a wire loopincorporated therein.

2. Description of the Related Art

Conventionally, in a process of fabricating a semiconductor device, asshown in FIG. 7A or 7B, wire bonding for connecting a pad 2 a or a firstbonding point A of a semiconductor chip 2 attached to a lead frame 1 anda lead 1 a or a second bonding point Z of the lead frame 1 through awire 3 has been carried out. Typically, loop shapes of the wire 3connecting the first and second bonding points A and Z include atrapezoidal shape and a triangular shape shown in FIGS. 7A and 7B,respectively, as disclosed, for example, in U.S. Pat. No. 6,036,080 orJapanese Patent Application Laid-Open Publication No. 2000-277558.

The wire loop having a trapezoidal shape shown in 7A is formed by asequence of steps as shown in FIG. 8. First, in step (a) of FIG. 8, acapillary 4 through which the wire 3 passes is lowered and a ball 30which has been formed at a tip end of the wire 3 is bonded to the pad 2a of the chip 2 or first bonding point A. Then, in step (b) of FIG. 8,the capillary 4 is vertically raised to a point B while the wire 3 isdelivered. Thereafter, in step (c) of FIG. 8, the capillary 4 ishorizontally moved to a point C in a direction opposite from the secondbonding point Z.

In general, such an operation of the capillary 4 to be moved in thedirection opposite from the second bonding point Z is referred to as a“reverse operation”. As a result, the portion of the wire 3 between thepoints A and C is formed to be inclined and the wire 3 is formed at anupper end of the inclined portion thereof with a kink 3 a by a lower endof the capillary 4. The portion of the wire 3 between the points A and Cthus delivered corresponds to the height of a neck portion H (or aportion of the wire 3 between the pad 2 a and the kink 3 a) and willconstitute the neck portion H.

Subsequently, in step (d) of FIG. 8, the capillary 4 is verticallyraised to a point D while the wire 3 is delivered. Then, in step (e) ofFIG. 8, the reverse operation of the capillary 4 is performed again,i.e. the capillary 4 is horizontally moved to a point E in the directionopposite from the second bonding point Z. As the result of this reverseoperation, the wire 3 has another inclined portion extending between thepoints C and E, and a kink 3 b is formed in an upper end of thisinclined portion of the wire 3.

This inclined portion of the wire 3 thus delivered will constitute anupper base portion L (or a portion of the wire 3 between the kinks 3 aand 3 b) of the wire loop having a trapezoidal shape shown in FIG. 7A.Thereafter, in step (f) of FIG. 8, the capillary 4 is vertically raisedto a point F so that the wire 3 is delivered by a length correspondingto a long inclined portion S (or a portion of the wire 3 between thekink 3 b and the lead 1 a) of the wire loop shown in FIG. 7A.Subsequently, the capillary 4 is lowered to the second bonding point Zvia positions f₁ and f₂, so that the wire 3 is bonded to the secondbonding point Z or the lead 1 a.

The wire loop having a triangular shape shown in 7B is formed by asequence of steps as shown in FIG. 9. Since the wire loop having atriangular shape is not provided with an upper base portion (L) unlikethe wire loop having a trapezoidal shape described above, in forming thewire loop of a triangular shape, the second reverse operation in steps(d) and (e) of FIG. 8 is not conducted. Therefore, in this instance, astep that corresponds to the steps (d), (e) and (f except for f₁ and f₂)of FIG. 8 is carried out only in step (d) of FIG. 9. More particularly,steps (a), (b) and (c) of FIG. 9 are the same as the steps (a), (b) and(c) of FIG. 8, and after the first reverse operation in step (c) of FIG.9, the capillary 4 is vertically raised to a point F in step (d) of FIG.9 while the wire 3 is delivered. Subsequently, in step (e) of FIG. 9,the capillary 4 is moved via positions e₁ and e₂ in a manner similar tothat in step (f) of FIG. 8, with the result that the wire 3 is bonded tothe second bonding point Z or the lead 1 a.

However, in the above-described techniques, as the wire loop includesthe neck portion H having a somewhat large height, the wire loop becomeshigh and thus is rendered to be unstable. In addition, in a case where awire loop is formed without any reverse operation of the capillary inorder to make the height of a neck portion H thereof small and theheight of the neck portion H is reduced to a certain level or below, theneck portion H is liable to be damaged in drawing or moving the wire 3to arrange it in place because of the wire 3 vertically extending fromthe first bonding point A.

SUMMARY OF THE INVENTION

The present invention has been made in view of the foregoingdisadvantages of the prior art.

Accordingly, it is an object of the present invention to provide a wireloop having a low profile which is stable and of which a neck portion ishard to be damaged.

It is another object of the present invention to provide a semiconductordevice having said wire loop incorporated therein.

It is still another object of the present invention to provide a wirebonding method capable of forming said wire loop.

It is a further object of the present invention to provide a wirebonding apparatus capable of carrying out said wire bonding method.

In accordance with one aspect of the present invention, a wire loop isprovided. The wire loop comprises: a wire connecting a first bondingpoint and a second bonding point therethrough; the wire including a ballbonded to the first bonding point, a neck portion adjacent to the balland a major portion extending from the neck portion to the secondbonding point; wherein the major portion of the wire has a crushed partformed in proximity to the neck portion by crushing the part of the wiretogether with a top portion of the ball.

In a preferred embodiment of the present invention, the neck portionincludes a first kink formed by a part of the neck portion being doubledover.

In a preferred embodiment of the present invention, the major portion ofthe wire includes a horizontal portion extending in a substantiallyhorizontal direction from the neck portion and an inclined portion whichextends from the horizontal portion to the second bonding point andwhich has an end thereof bonded to the second bonding point; and theinclined portion is connected to the horizontal portion through a secondkink formed in a part of the wire therebetween.

In a preferred embodiment of the present invention, the neck portionincludes at least one additional doubled over kink like the first kink.

In accordance with another aspect of the present invention, a wirebonding method for bonding a wire between a first bonding point and asecond bonding point using a capillary is provided. The wire bondingmethod comprises the steps of:

-   -   bonding a ball formed on a tip end of the wire to the first        bonding point;    -   moving the capillary horizontally and vertically while carrying        out loop control, to thereby form a kink in a neck portion of        the wire adjacent to the ball;    -   bonding the wire to a top or the vicinity of the top of the ball        bonded to the first bonding point; and    -   thereafter, moving the capillary horizontally and vertically to        the second bonding point while delivering the wire from the        capillary and carrying out loop control, and then bonding the        wire to the second bonding point;    -   wherein the step includes crushing a part of the wire and the        top of the ball with the capillary to form a crushed part in the        wire.

In a preferred embodiment of the present invention, in the steps (b) and(c), the neck portion of the wire is doubled over to form the kink.

In a preferred embodiment of the present invention, the steps (b) and(c) are repeatedly carried out a plurality of times to form at least oneadditional doubled over kink in the neck portion.

In a preferred embodiment of the present invention, the step (d)includes operating the capillary to form an additional kink in a portionof the wire located between the crushed part and the second bondingpoint.

In accordance with still another aspect of the present invention, a wirebonding apparatus for carrying out the wire bonding method is provided.The wire bonding apparatus comprises: a capillary having the wireinserted therethrough to deliver the wire from the capillary; a clampfor releasably clamping the wire; a moving means for moving thecapillary horizontally and vertically; a control unit for controllingthe movement of the capillary; and a means for manually inputting heightof the capillary to be raised into the control unit, whereby themovement of the capillary is automatically controlled.

In accordance with a further aspect of the present invention, asemiconductor device is provided. The semiconductor device comprises: afirst bonding point; a second bonding point; a wire bonded to the firstbonding point and the second bonding point to connect the first bondingpoint and the second bonding point therethrough; wherein the wireincludes a ball bonded to the first bonding point, a neck portionadjacent to the ball and a major portion extending from the neck portionto the second bonding point; and wherein the major portion of the wirehas a crushed part formed in proximity to the neck portion by crushingthe part of the wire together with a top portion of the ball.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and many of the attendant advantages of thepresent invention will be readily appreciated as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings; wherein:

FIG. 1A is an elevational view showing a shape of an embodiment of awire loop in a semiconductor device according to the present invention;

FIG. 1B is a fragmentary schematic plan view showing the semiconductordevice;

FIG. 2 is a schematic elevational view showing a moving path of acapillary to form the wire loop having a shape shown in FIG. 1 and astate of connection of the wire loop;

FIG. 3 is a schematic diagram showing wire shapes in respective steps inassociation with the movement of the capillary according to a method ofthe present invention by way of example;

FIG. 4 is an elevational view showing a shape of another embodiment of awire loop in a semiconductor device according to the present invention;

FIG. 5 is an elevational view showing a shape of still anotherembodiment of a wire loop in a semiconductor device according to thepresent invention;

FIG. 6 is a block diagram showing an embodiment of a wire bondingapparatus according to the present invention;

FIGS. 7A and 7B are elevational views showing conventional wire loopshaving a trapezoidal shape and a triangular shape, respectively;

FIG. 8 is a schematic diagram showing wire shapes in respective steps inassociation with the movement of the capillary to form the wire loop ofa trapezoidal shape shown in FIG. 7A; and

FIG. 9 is a schematic diagram showing wire shapes in respective steps inassociation with the movement of the capillary to form the wire loop ofa triangular shape shown in FIG. 7B.

DETAILED DESCRIPTION OF THE INVENTION

Now, a wire loop, a semiconductor device, a wire bonding method and awire bonding apparatus according to the present invention will bedescribed hereinafter with reference to the accompanying drawings inwhich like parts in each of the several figures are identified by thesame reference character or numeral.

Referring first to FIGS. 1A and 1B, an embodiment of a wire loop and asemiconductor device 10 having the wire loop incorporated thereinaccording to the present invention is illustrated. In the semiconductordevice 10, a semiconductor chip 2 is attached to a lead frame 1 and isprovided thereon with a pad 2 a which is a first bonding point A. Thewire loop of a wire 3 is formed to have a trapezoidal shape in generaland includes a neck portion H having a ball 30 bonded to the pad 2 a orfirst bonding point A and a major portion consisting of a horizontalupper portion L and an inclined portion S which has an end bonded to alead 1 a of the lead frame 1 or a second bonding point Z. The horizontalupper portion L of the wire loop is provided at the opposite endsthereof with kinks 3 a and 3 b.

Such construction of the illustrated embodiment is approximately thesame as that of a conventional semiconductor device. However, in theillustrated embodiment, a crushed part 3 c is formed in the wire 3 inthe vicinity of the first bonding point A. More specifically, thecrushed part 3 c is formed in the horizontal upper portion L of the wire3 adjacent to the kink 3 a by crushing the part of the wire 3 togetherwith a top portion of the ball 30. As the wire loop has the crushed part3 c thus formed adjacent to the kink 3 a, the kink 3 a is stablydeformed, resulting in the wire loop having a low profile and exhibitinga strong shape retention.

Referring now to FIGS. 2 and 3, an embodiment of the wire bonding methodaccording to the present invention by which the semiconductor device 10shown in FIGS. 1A and 1B is obtained will be described.

FIG. 2 shows a moving path P of a capillary 4 and a finished state ofthe wire loop connected to the first and second bonding points A and Zby wire bonding. As compared to the conventional method shown in FIG. 8,the illustrated embodiment of the wire bonding method further includessteps (e) and (f) of FIG. 3 which are carried out between steps (d) and(e) of FIG. 8. The remaining steps of FIG. 3 are the same as those ofFIG. 8, i.e. steps (a) to (d) and steps (g) to (k) of FIG. 3 correspondto the steps (a) to (d) and the steps (e) and (f [via positions f₁ andf₂]) of FIG. 8.

First, steps (a) to (d) of FIG. 3, which are the same as those in theconventional method, will be described. In FIG. 3, a clamp 5 used forclamping a wire 3 and releasing the same is illustrated in such a mannerthat a closed state of the clamp 5 and an open state thereof areindicated by contacting the clamp 5 with the wire 3 and by separating itfrom the wire 3, respectively, and that a case in which the clamp 5 maybe kept in either the closed state or open state is indicated bydiagonal lines added in the clamp 5. In step (a) of FIG. 3, thecapillary 4 is lowered while the clamp 5 is opened, so that a ball 30formed on a tip end of the wire 3 is bonded to the first bonding pointA. Then, in step (b) of FIG. 3, the capillary 4 is vertically raised toa point B while the wire 3 is delivered. Thereafter, in step (c) of FIG.3, a reverse operation of the capillary 4 is carried out, i.e. thecapillary 4 is horizontally moved in a direction opposite from thesecond bonding point Z to a point C. As a result, a kink 3 a is formedin the wire 3 in the same manner as in the conventional method.

Thereafter, the capillary 4 is vertically raised to a point D1 which maybe selected as desired while the wire 3 is delivered. Then, important orcharacteristic steps of the embodiment of the present invention areperformed. More specifically, in step (e) of FIG. 3, the capillary 4 ismoved in a direction toward the second bonding point Z to a point D2which is located almost immediately above the first bonding point A andof which the vertical and horizontal positions may be determined asdesired. Subsequently, the wire 3 is bonded to a point M1 in such amanner that a part of the wire 3 is crushed together with a top portionof the ball 30 bonded to the first bonding point A. As the result ofthis operation, a crushed part 3 c is formed in the wire 3 adjacent tothe kink 3 a while the kink 3 a is formed into a shape in which the partof the wire 3 is doubled over. Then, in step (g) of FIG. 3, thecapillary 4 is vertically raised to a point D while the wire 3 isdelivered. In this instance, the capillary 4 may be slightly moved in ahorizontal direction toward the second bonding point Z and thenvertically raised to a point (not shown) which is slightly deviated fromthe point D. Alternatively, the capillary 4 may be obliquely raised tothe slightly deviated point. Thus, in steps (e) and (f) of FIG. 3, thecrushed part 3 c is formed in the wire 3.

Then, in step (h) of FIG. 3, a second reverse operation of the capillary4 is performed. That is, the capillary 4 is horizontally moved in adirection opposite from the second bonding point Z to a point E. Themovement of the capillary 4 form the point D to the point E forms a kink3 b in the wire 3. Thereafter, in step (i) of FIG. 3, the capillary 4 isvertically raised to a point F so that the wire 3 is delivered by alength which corresponds to the inclined portion S of the wire 3extending between the kink 3 b and the lead 1 a.

Subsequently, steps (j) and (k) of FIG. 3 are conducted in the samemanner as that in the conventional method described above such that thecapillary 4 is lowered to be located at the second bonding point Z,resulting in the wire 3 being bonded to the second bonding point Z.Incidentally, the movement of the capillary 4 from the point F to thesecond bonding point Z may be carried out along the same path as that inthe conventional method described above, or may be suitably selectedfrom various possible paths.

As described above, the second bonding of the wire 3 to the point M1located almost the above the first bonding point A or in the vicinitythereof is carried out in step (f) of FIG. 3, not after the capillary 4being merely raised as in step (b) of FIG. 3. Instead, the secondbonding in step (f) of FIG. 3 is conducted after the capillary 4 ishorizontally moved in the direction opposite from the second bondingpoint Z in step (c) of FIG. 3 and the kink 3 a is formed in the wire 3by performing steps (d) and (e) of FIG. 3, whereby the crushed part 3 cis formed in the wire 3. As a result, the neck portion H is crushed ordeformed to have a reduced height which is substantially equal to aheight of the horizontal portion L per se extending between the kinks 3a and 3 b, with the result that the wire loop having a low profile canbe formed. For example, when a gold wire having a thickness of 25 μm iswire bonded to form a bonded part which has a diameter of about 60 μmand a thickness of about 12 μm, the neck portion H has a height of about50-80 μm according to the present invention, whereas the neck portion Hhas a height of about 100-130 μm according to the conventional method.In addition, since the crushed part 3 c of the wire 3 is bonded to theposition M1 immediately above the first bonding point A, a rising partof the wire 3 from the first bonding point A is formed to be strong ascompared to that of the conventional wire loop, with the result that awire loop which is stably positioned and which has a strong shaperetention can be formed.

Furthermore, in order to control the height of the neck portion Himmediately above the first bonding point A or control a damage possiblycaused to the neck portion H, the operations in steps (b) to (f) of FIG.3 with respect to the point M1 immediately above the first bonding pointA or the vicinity thereof may be repeatedly carried out twice or moretimes. Embodiments of wire loops formed by carrying out such wirebonding with respect to the first bonding point A a plurality of timesare shown in FIGS. 4 and 5 by way of example.

The wire loop shown in FIG. 4 is provided at the neck portion H withkinks 3 a ₁ and 3 a ₂ which are formed by varying a distance which thecapillary 4 is horizontally moved in step (c) of FIG. 3. Morespecifically, the distance the capillary 4 is horizontally moved forforming the kink 3 a ₂ is slightly shorter than that for forming thekink 3 a ₁.

The wire loop shown in FIG. 5 is provided at the neck portion H withthree kinks 3 a ₁, 3 a ₂ and 3 a ₃ which are formed by varying, inaddition to a distance, a direction in which the capillary 4 ishorizontally moved in step (c) of FIG. 3. The kinks 3 a ₁ and 3 a ₃ areformed by moving the capillary 4 in the same direction opposite from thesecond bonding point Z and different distances, whereas the kink 3 a ₂is formed by moving the capillary 4 in a direction toward the secondbonding point Z in step (c) of FIG. 3.

As described above, in the embodiments of the wire bonding methodaccording to the present invention, the bonding operation in accordancewith steps (b) to (f) of FIG. 3 is carried out at least one time.

The bonding method of the present invention is performed, for example,by a wire bonding apparatus shown in FIG. 6. The bonding apparatusincludes a base 20, an X-Y table 22 mounted on the base 20, a z-axismoving mechanism 24, a control unit 32 and a servo driving andcontrolling section 33 for controlling the X-Y table 22 and the z-axismoving mechanism 24 through x-, y- and z-axis motors 21, 23 and 26. Theapparatus also includes a bonding stage 28 on which a lead frame 1 isplaced. The z-axis moving mechanism 24 is provided with an arm 27 whichhas a capillary 4 attached to a distal end thereof while a wire 3 isinserted through the capillary 4. A clamp 5 is arranged above thecapillary 4 so as to clamp and release the wire 3. Such constructionpermits the capillary 4 to be moved between a pad 2 a (or a firstbonding point A) of a semiconductor chip 2 attached to the lead frame 1and a lead 1 a (or a second bonding point Z) of the lead frame 1 whileloop control is carried out. The z-axis moving mechanism 24 is supportedby a pivot 25 such that the distal end of the arm 27 is vertically movedby the z-axis motor 26.

The control unit 32 is adapted to output a control signal to the servodriving and controlling section 33 on the basis of parameters which arepreviously set therein such that the servo driving and controllingsection 33 moves the capillary 4 to and from the first and secondbonding points A and Z along a predetermined path and operates thecapillary 4 and the clamp 5. The control unit 32 is provided with amanual input section 34 attached thereto to input parameters, such aspositions of the capillary 4 in horizontal and vertical direction duringthe wire bonding operation, in the control unit 32. Thus, the height ofthe capillary 4 to be raised is manually inputted into the control unit32 through the manual input section 34, whereby the movement of thecapillary 4 is automatically controlled. In FIG. 6, reference numerals30, 35 and 36 denote a ball formed at a tip end of the wire 3, an ITVcamera and an image recognition section, respectively.

The apparatus thus constructed suitably performs the wire bonding asdescribed above with reference to the embodiment of the method of thepresent invention.

As can been seen from the foregoing, in the wire bonding method and thewire bonding apparatus, the wire loop connecting the first bonding pointand the second bonding point therethrough is provided on the neckportion thereof with the crushed part which is formed by crushing a partof the wire in proximity to the neck portion together with the topportion of the ball bonded to the first bonding point. Such constructioncan provide a wire loop having a low profile which is stable and strongin shape retention. Such a shape of the wire loop can be readilyobtained by, after bonding the ball of the wire to the first bondingpoint, raising the capillary slightly, carrying out loop control, andthereafter bonding the wire to the top or the vicinity of the top of theball.

Therefore, not only a wire loop having a short wiring distance but alsoa wire loop having a long wiring distance can be obtained as a stablewire loop having a low profile. In addition, the wire loop thus formedhas a strong shape retention which withstands a force or pressureexerting on the wire loop from outside. Therefore, the wire loop canperform an excellent shock absorbing function against a shock, such as ashock caused by contact of the capillary or emission of an ultrasonicwave during bonding the wire to the second bonding point, vibration ofthe wire, an external force generated by flow of a molding materialduring injection of the molding material and the like, with the resultthat bending or tilting of the wire and a breakage in the neck portionof the wire loop can be effectively prevented.

While preferred embodiments of the invention have been described with acertain degree of particularly with reference to the drawings, obviousmodifications and variations are possible in light of the aboveteachings. It is therefore to be understood that within the scope of theappended claims, the invention may be practiced otherwise than asspecifically described.

1-5. (canceled)
 6. A wire bonding method for bonding a wire between afirst bonding point and a second bonding point using a capillary,comprising the steps of: (a) bonding a ball formed on a tip end of thewire to said first bonding point; (b) moving said capillary horizontallyand vertically while carrying out loop control, to thereby form a kinkin a neck portion of the wire adjacent to said ball; (c) bonding thewire to a top or the vicinity of the top of said ball bonded to saidfirst bonding point; and (d) thereafter, moving said capillaryhorizontally and vertically to said second bonding point whiledelivering the wire from said capillary and carrying out loop control,and then bonding the wire to said second bonding point; wherein theabove steps include crushing a part of the wire and the top of said ballwith said capillary to form a crushed part in the wire.
 7. The wirebonding method as defined in claim 6, wherein in the steps (b) and (c),said neck portion of the wire is doubled over to form said kink.
 8. Thewire bonding method as defined in claim 6, wherein the steps (b) and (c)are repeatedly carried out a plurality of times to form at least oneadditional doubled over kink in said neck portion.
 9. The wire bondingmethod as defined in claim 7, wherein the steps (b) and (c) arerepeatedly carried out a plurality of times to form at least oneadditional doubled over kink in said neck portion.
 10. The wire bondingmethod as defined in claim 6, wherein the step (d) includes operatingsaid capillary to form an additional kink in a portion of the wirelocated between said crushed part and said second bonding point.
 11. Thewire bonding method as defined in claim 7, wherein the step (d) includesoperating said capillary to form an additional kink in a portion of thewire located between said crushed part and said second bonding point.12. The wire bonding method as defined in claim 8, wherein the step (d)includes operating said capillary to form an additional kink in aportion of the wire located between said crushed part and said secondbonding point.
 13. A wire bonding apparatus for carrying out a wirebonding method of claim 6, comprising: a capillary having the wireinserted therethrough to deliver the wire from said capillary; a clampfor releasably clamping the wire; a moving means for moving saidcapillary horizontally and vertically; a control unit for controllingthe movement of said capillary; and a means for manually inputtingheight of said capillary to be raised into said control unit, wherebythe movement of said capillary is automatically controlled. 14-16.(canceled)
 17. A wire bonding method for bonding a wire between a firstbonding point and a second bonding point, comprising the steps of:bonding a first end of a predetermined length of wire to the firstbonding point; moving an adjacent portion of the wire relative to thefirst end in a first direction away from the first bonding point andsubsequently bending the wire to the wire to extend back in a seconddirection over the first bonding point to contact the adjacent portionat the first bonding point; moving a second end of the predeterminedlength of wire in a third direction to contact the second bonding point;and bonding the second end to the second bonding point.
 18. The wirebonding method as defined in claim 17 wherein the subsequent bending ofthe wire back in a second direction includes crushing the overlayingwire together with the adjacent portion of the wire.
 19. The wirebonding method as defined in claim 17 wherein the wire is bent tooverlap itself twice at the first bonding point.
 20. The wire bondingmethod as defined in claim 17 wherein the first end has a ball formed ona tip of the first end for bonding.
 21. A wire bonding method forproviding a wire loop connector for electrical connection between asemiconductor device and a lead frame comprising the steps of: providinga wire body of a predetermined length; bonding a first end of the wirebody to the semiconductor device; moving an immediately adjacent portionof the wire body where the wire body is bonded to the semiconductordevice to overlap and form a double overall thickness of the wire bodyat the electrical connection of the bonded first end; and bonding asecond distal end of the wire body for electrical connection with thelead frame having a thickness of the wire body wherein the height of thewire body relative to a distance above the semiconductor device isrestricted.
 22. The improved wire loop connection of claim 21 furtherincluding at the first end of the wire body a second overlaid length ofthe wire body wherein a thickness is quadruple the overall thickness ofthe wire body.
 23. The improved wire loop connection of claim 21 whereinthe wire body has been bent four times to integrally form an overallthickness with each bent length closed upon another length of the wirebody.